Development and Application of the Korea Ozone Weather Index (KOWI) for Future Projections of High Surface Ozone Episodes over the Korean Peninsula

In this study, we develop the Korea Ozone Weather Index (KOWI) to quantify changes in meteorological factors that contribute to the formation of environments conducive to high surface ozone episodes (ECHO) over the Korean Peninsula (KP). Our results confirm that KOWI effectively represents observed variations in ECHO over the KP. Based on this, we analyze future changes in ECHO using simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6), comparing scenarios with no additional mitigation efforts (SSP3-7.0), air quality control policies (SSP3-7.0-lowNTCF), and both air quality controls and greenhouse gas (GHG) emission reductions (SSP1-2.6).

The CMIP6 ensemble projects that the annual occurrence of ECHO during the May–September period will increase from 24.1 days (1995–2014) to 103.8 days (SSP3-7.0), 112.8 days (SSP3-7.0-lowNTCF), and 76.2 days (SSP1-2.6) in the 2081–2099 period. These results indicate that air quality control policies alone are insufficient to mitigate the increase in ECHO, and that a combination of air quality controls and GHG emission reductions is necessary.  And it is confirmed that the maximum temperature and downward solar radiation factors have significant a contribution on changes in ECHO. Additionally, our presentation will introduce the methodology and preliminary findings on regional-scale changes in ECHO based on the KOWI index.